Many sectors, from retail to transportation to health-care and beyond, are driven by continuous streams of input events. Computers process such events quickly and automatically, for example, based on event-processing rules, for example, authored by users. Implementing automated tools or computer systems that allow users to author event-processing rules, for instance, through natural language intuitively, remains a challenge. While event-processing rules may be written in a controlled natural language (CNL), users still need to learn the language in order to author the rules. Existing solutions to rule authoring have attempted to simplify event-processing rule language. However, over-simplification of rules limits their expressiveness. Other prior solutions for aiding the authoring of event processing rules include graphical interfaces and spreadsheets.